Fluidized-bed or teeter-bed separation systems are used for classification and density separation within the mining industry. The metallurgical performance and high capacity of these separation systems make them ideal for feed preparation prior to flotation circuits. It has been found that when this type of separation system implements a fluidization flow with the addition of air bubbles, performance can be improved beyond that achieved by systems using only water. This variety of separator is called an air-assisted separation system. These devices are typically controlled using two basic operating parameters: fluidization flow rate and fluidized bed level. What is presented are improvements to an air-assisted separation system, incorporating various novel features, that further enhance the separation process.